1970GeorgiaZ28
New Member
- Aug 15, 2019
- 27
What 4 speed came in a 70 Z28? Casting numbers etc? thanks
What 4 speed came in a 70 Z28?
- Thread starter 1970GeorgiaZ28
- Start date
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Main case casting number ends in 661. The first year for that casting I believe.
Two close ratio trans available, the M21 and M22 heavy duty(aka rockcrusher) with a 2.20:1 first gear and a wide ratio M20 with a 2.52:1 first gear. The stamped number on the side of the main case will start with a P for Muncie and end in a A for the M20, B for the M21 and C for the M22.
Two close ratio trans available, the M21 and M22 heavy duty(aka rockcrusher) with a 2.20:1 first gear and a wide ratio M20 with a 2.52:1 first gear. The stamped number on the side of the main case will start with a P for Muncie and end in a A for the M20, B for the M21 and C for the M22.
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